Corrosion-resistant diaphragm valve and assembling method thereof

A corrosion-resistant diaphragm valve, comprising:

• a valve cover, wherein the valve cover is internally provided with a pneumatic piston member that is configured to elastically push outwards, a fixed non-rotatable supporting block is provided in a first lower opening, a guided diaphragm pressing block is provided in a second lower opening of the fixed non-rotatable supporting block, and the guided diaphragm pressing block is connected to a first end of the pneumatic piston member;
• a film diaphragm sheet coupled to the pneumatic piston member, wherein the film diaphragm sheet has a valve head connected to the first end of the pneumatic piston member, a bending portion extending outwards from the valve head, and a clamping portion extending outwards from the bending portion;
• the clamping portion is provided with a plurality of peripheral through holes or notches;
• and a straight sealing convex strip extending through the valve head is disposed at a bottom of the film diaphragm sheet;
• and
• a valve seat coupled with the valve cover by a first connector, wherein the first connector passes through the plurality of peripheral through holes or notches of the film diaphragm sheet to connect to the valve cover to clamp the clamping portion of the film diaphragm sheet;
• and
• wherein a thickness of the clamping portion of the film diaphragm sheet is sufficient so that the valve seat is not in direct contact with the valve cover;
• the valve seat is internally provided with a first runner and a second runner separated by an arc-shaped dam, the first runner and the second runner are in communication with each other at adjacent ends of the first runner and the second runner to form a curved runner structure, and in a horizontal section along an axis of the first runner and the second runner, a curved runner C-shaped opening is provided in the curved runner structure, which is bent upwards in a flattened curve;
• and when the corrosion-resistant diaphragm valve is closed, the straight sealing convex strip is aligned with and pressed against the arc-shaped dam.